Postoperative aspiration pneumonitis is a cause for concern among the anesthesiologists. Gastric acidity may be at its peak after overnight fasting and during the day when the patient comes for elective surgery. The odds of aspiration and its sequelae, if it does occur, can be minimized with preventive measures.

In line with this, Bhattacharya et al compared the effects of preoperative oral ranitidine with those of pantoprazole on regulation of gastric pH in elective surgery.

This was a prospective, parallel group, controlled, randomized, single-blind study, carried out at a tertiary care postgraduate teaching institute at Kolkata, India. It included 120 subjects, 18-60 years of age, of American Society of Anesthesiologists physical status I and II. The participants had to undergo elective surgery under general anesthesia lasting over 2 h.

The investigators segregated the participants into three groups with 40 participants each - Group A received placebo tablet, group B received ranitidine tablet, and group C was given pantoprazole tablet. The participants were given the drugs on the day before the surgery at 9 p.m and at 6 a.m. on the day of surgery. The gastric pH was measured serially. The study subjects were comparable in terms of age, sex, body weight, duration of surgery and type of surgery distribution.

Findings of the study -

• There appeared to be no statistically significant difference between serial pH values in group A and group C in terms of changes in gastric pH trends (P>0.05).
• The mean preoperative gastric pH values were significantly lower than mean pH values after 2 h postoperatively in group B participants (7.140±0.7652 vs. 7.253±0.7514; P<0.05).

The mean gastric pH in the preoperative, intraoperative and postoperative periods is summarized in Table 1.

Table 1. Mean gastric pH in the preoperative, intraoperative and postoperative periods in study subjects

Based on the results, the investigators concluded that ranitidine is more effective in increasing the gastric pH for prevention of aspiration pneumonitis, compared to pantoprazole.

Source: Bhattacharyya T, Sarbapalli D, Pal R, et al. Evaluating ranitidine, pantoprazole and placebo on gastric pH in elective surgery. Saudi J Anaesth. 2011 Jan-Mar; 5(1): 67–72